The disclosed embodiments relate to the area of distributed printing and contemplates distributing print job portions among two or more printing devices pursuant to a technique that uses information about the actual or effective outputs of the respective printing devices to permit printing of the print job portions to end substantially simultaneously.
Known distributed printing systems, such as client/server printing networks, include one or more servers and multiple printers associated with the server. In such systems, first-in-first-out (FIFO) queuing is often used. Typically, a job from a particular user is sent to a particular user-defined and selected printer. Such a system does not optimally utilize its resources, as certain printers inevitably handle more job requests than other available printers. In such a scenario, one particular printer may have a long job queue and long delay times in printing while other networked printers are in an idle state (i.e., not in current use).
Distributed printing systems have been designed in an attempt to improve on this by providing some degree of load balancing. In such systems, if a selected output device is in use, the job request will be spooled to an available printer within the distributed system or print “cluster.” Such a system may provide limited load balancing by, for instance, distributing a 1/N job portion to each one of N target printers.
An improvement to the above-described distribution scheme disclosed in U.S. Pat. No. 5,978,560 to Tan et al. where job portions (e.g., groups of job sets) are distributed within a distributed printing system based on more detailed information about the particular attributes of each output device. It is also known, as disclosed by U.S. Pat. No. 5,287,194 to Lobiondo, that jobs can be partitioned prior to distribution within a distributed printing system:                If the network has available printers, but a single printer is incapable of completing the job by a required time, the scheduler can allocate portions of the job to a plurality of printers which can print the job in parallel to speed up the completion time to meet the requested time constraints. This may include allocating or dividing the job between a plurality of printers at locations remote from one another. The user is then informed where the job is being printed and when completion is expected.        
Various prior art disclosures contemplate the use of some “intelligence” in distributing parts of a print job within a distributed printing environment. For instance, U.S. Pat. No. 6,825,943 to Barry et al. discloses a method in which a print job is partitioned into select portions according to defined boundaries; a substitute RIP instruction is generated for each select portion of the print job; and the RIP requirements of each select portion is processed in an assigned one of a plurality of RIP engines according to the substitute RIP instruction. Additionally, U.S. Pat. No. 5,995,721 to Kishida relates generally to a distributed printing system with a plurality of document processing subsystems where the attributes of a document are examined for the purpose of delivering multiple portions of the document to multiple ones of the plurality of document processing subsystems on the basis of the examination.
U.S. Pat. No. 6,930,795 to Motamed et al. discloses software for, among other things, (1) routing jobs to the most available printer based on color use, pages per minute, number of pages per said job, size, and number of copies for jobs already in a queue and number of copies of the job sent, (2) automatically splitting job copies across specified number of printers meeting job criteria, (3) automatically splitting a single copy that is a long job across more than one printer, (4) supporting mixed groups of printers, wherein they do not all need to be the same make and model, (5) monitoring the status of a print job and redirecting the job if an error occurs, (6) supporting job scheduling by allowing a user to specify job priority, with password required for rush jobs, and for specifying job rip and print scheduling in advance, and (7) supporting specified non-proprietary black and white printers.
The pertinent portions of the above-mentioned patents are incorporated herein by reference
The prior art systems do not appear to appreciate the value of splitting a job, for the purpose of sending resulting portions to target printing devices in a distributed printing arrangement, proportionate to the respective output rates of the target printing devices. Without such appreciation, however, it appears difficult to distribute the resulting portions across the target printing devices and complete printing of the portions substantially simultaneously. It would therefore be desirable to provide a system that splits a job proportionate to the print speeds of the target printing devices.
Additionally, the above-described print distribution systems are not necessarily well suited for operation in an environment where the operation of at least one of the distributed or clustered print devices deviates from its rated output. In particular, it is known that execution of a significant number of job requirements can cause a given printer to produce prints above or below its anticipated rated output. In one example, a printer may produce prints at a lower than expected rate when operating in an “emulation mode.” In another example, the same printer may produce prints at higher than expected output rate (i.e., at an effective rate that is higher than the rated output) when two or more copies of the same image are printed on the same side of a single print media side in a “plural-up” printing mode, and the resulting multi-image output sheets are then cut into single image sheets. For the sake of accurately splitting a print job, for delivery of the portions to the target printing devices of a distributed printing arrangement, it would be desirable, pursuant to job splitting, to know the projected effective output rate of the target printing device in the distributed printing arrangement.
Finally, a suitable splitting of the print job may not be achievable unless a full understanding of the operational modes of each target printing device is obtained. For instance, adding an image processing capability for one target printing device, such as “image quality interoperability (a feature provided in selected printing devices sold by Xerox Corporation)” may decrease the effective output rate of a target printing device, while a plural-up capability, as described above, may increase the effective output rate of the target printing device. It would be desirable, pursuant to job splitting, to fully comprehend the operational capabilities of the target printing devices to which the respective job portions are to be sent.
In accordance with one aspect of the disclosed embodiments, there is provided a print job distribution system for printing a print job. The print job distribution system includes: a print job distribution controller; a distributed printing arrangement communicating with the print job distribution controller, the print job distribution arrangement including a first printing system having a first rated output and a second printing system having a second rated output; the first and second printing systems having first and second default operating modes, respectively, and the second printing system having an adjusted operating mode with an effective output that differs from either the first rated output or the second rated output; a print job distribution application for operation with the print job controller; and the print job distribution application being adapted to split the print job into first and second print job portions, the first and second print job portions being split in such a way that when (a) both the first and second print job portions are communicated to the distributed printing arrangement, (b) the first print job portion is printed at the first printing system in the first default operating mode, and (c) the second print job portion is printed at the second printing system in the adjusted operating mode, printing of the first and second print job portions end substantially simultaneously.
In accordance with another aspect of the disclosed embodiments, there is provided a print job distribution system for printing a print job. The print job distribution system includes: a print job distribution controller; a distributed printing arrangement communicating with the print job distribution controller, the print job distribution arrangement including a first printing system operable in a first default operating mode in which a first set of default features is made available and a second printing system operable in a second default operating mode in which a second set of default functions is made available; the second printing system being operable in an enhanced operating mode in which a third set of features is made available, the third set of features including at least one more feature than is available in the second set of default features; a print job distribution application for operation with the print job controller; and the print job distribution application being adapted to split the print job into first and second print job portions, the first and second print job portions being split in such a way that when (a) both the first and second print job portions are communicated to the distributed printing arrangement, (b) the first print job portion is printed at the first printing system in the first default operating mode, and (c) the second print job portion is printed at the second printing system in the enhanced operating mode, printing of the first and second print job portions end substantially simultaneously.
In accordance with yet another aspect of the disclosed embodiments, there is provided a method for managing a print job in a distributed printing system including a first printing system having a first default operating mode with a first rated output and a second printing system having a second default operating mode with a second rated output. The method includes: determining that the second printing system has the capability to operate in an adjusted operating mode with an effective output that differs from either the first rated output or the second rated output; and splitting the print job into first and second job portions in such a way that when (a) both the first and second print job portions are communicated to the distributed printing arrangement, (b) the first print job portion is printed at the first printing system in the first default operating mode, and (c) the second print job portion is printed at the second printing system in the adjusted operating mode, printing of the first and second print job portions end substantially simultaneously.